Electromagnetic switch



March 18, 1947- J. F. O'BRIEN E-rAL ELECTROMAGN'ETIC SWITCH Filed Oct.30, 1943 2 Sheets-SheetY l ...f/linffflllv* INVENToRs OSEPH F. OBRIENTORNBY L S.BOYNTON BY March 1s. 1941. J. F; @BRIEN Em 2,411,438

ELECTROIIAGNETIC SWITCH 2 Sheets-Sheet 2 Filed Oct. 30, 1943 PatentedMar. 18, 1947 2,417,438 ELECTROMAGNETICl SWITCH Joseph F. OBrien, JerseyCity, and Earl S. Boynton, East Orange, N. J., assignors to John B.Pierce Foundation, New York, N. Y., a corporation of New YorkApplication October 30, 1943, Serial No. 508,298

7 claims. `(ci. 11s-341) l This invention relates to electromagneticswitches.

It is an object of the invention to provide an improved structuralorganization of the operatlng parts of said electromagnetic switch, toinsure that all of the respective operating parts are preciselypositioned .within the electromagnetic switch housing.

It is an object of the invention to provide an electromagnetic switch inwhich a snap spring or like operating structure, by solenoid inducedmovement, opens or closes the contacts of the electromagnetic switch,the relative position of the snap spring and the solenoid operator beingdisposed within the casing in a pre-established dimensional arrangementto insure accuracy of operation. l

It is an object of the invention to provide improved means for confiningwithin the housing of a electromagnetic switch, the operating elementsthereof.

It is an object of the invention to provide a electromagnetic switchwith improved contact structures.

It is an object of the invention to provide an electromagnetic switchhaving a fixed and a movable contact organization, with improved meansfor cushioning the engagement between the xedand movable contact.

It is an object of the invention to provide an electromagnetic switchcomprising a plurality of operating parts, with improved means forsecuring said operating parts within a housing, with a minimum offastening or attachment means for said operating parts.

It is an object of the invention to provide an electromagnetic switchwhich is of simple, low cost construction, and which may be assembled,with accurately disposed securement of the operating parts, by means ofunskilled labor.

According to a preferred form of the invention, the improvedelectromagnetic switch comprises an organization of fixed and movablecontacts,

the movable contacts being brought into or out of engagement with thefixed contacts by solenoid actuators, operating through the agency of asnap spring. Secured to the base of the housing of the electromagneticswitch, on which base the xed contacts are positioned, are a pluralityof side frame members, said members having at a pre-determined locationwith respect to the base structure, means to receive and position asub-base which serves as the support for the operating elements of theelectromagnetic switch. Positioned upon said sub-base, but notpermanently affixed thereto, are a snap spring retainer and a solenoidactuator comprising a pair of individual solenoid cups between which,and in engagement with the rims thereof are located a pair of spacermembers having inner peripheral flanges which collectively provide acylindrical chamber within which a solenoid core is slidably positioned.The respective solenoid.cups, within which the operating solenoids arecontained, are in stacked relationship one with the other,

y and may be inserted within the side frame mem- -bers by the successiveplacing therein by the workman. Near the outerend of each of said sideframe members is an aperture adapted to receive the tongue of a, rigidbridge which over.- lies the outermost solenoid cup in spacedrelationship therewith. Said bridge member has any desired plurality oftapped openings which receive set screws or the like, the ends of whichbear against the top wall of the outermost solenoid cup. Upon tighteningthe set screws the respective operating elements are urged one againstthe other, and in tight relationship with the sub-base which forms thesupport for the collective operating members. y

The bridge member also aiords means of securing an outer casing and atop closure plate to complete the housing of the device.

The movable contacts are carried by a flexible plate operativelyassociated with the magnetic armature whereby the movable contacts areresiliently supported in a. manner aiiording self-adjustability withrespect to the fixed contacts. 'I'he flexible disc carrying the movablecontacts gives under the impact of the movable contacts against thefixed contacts thereby cushioning the same and dampening chatter duringthe making of the contacts, resulting in improved circuit closingcharacteristics and enhancing the life of the respective contacts. Y

A feature of our invention is an improved assembly structure for anelectromagnetic switch.

A feature of our invention is an improved contact organization for anelectromagnetic switch.

Other features and advantages will hereinafter appear. p

Fig. 1 is a sectional view of a preferred form of electromagnetic switchembodying the present invention; l

Fig. 2 is a central sectional view taken on line 2 2 or Fig. 1;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 1; y

Fig. 4 is a sectional view taken I on line 4 4 of Fig. 1;

a,417,4ss

Fig. 5 is another sectional elevation of the device, in closed circuitposition, the line of section being onthe line 5-5 of Fig. l;

Fig. 6 is an exploded perspective view of the structure; and

Fig. 7 is a side elevationpartly broken away,

of the assembled structure, with the outer casing broken away toillustrate the positioning of the parts; Fig. 7 also shows a typicalwiring diagram.

Referring to the drawings, the housing of our improved electromagneticswitch I0 includes a base plate II, shell I2 and cap I4; these parts areof insulating material. Secured to the base plate II, as by any desiredplurality of screws or rivets, is an open frame comprising side piecesI5, I6 within which the operating elements of the electromagneticswitchare contained and secured. As shown in Figs. 1 and 6, each frame member,at a location suitably above the base, has a pair of ears I1, I1 struckinwardly in a common plane; upon said ears rests a plate I8 which servesas a base for the solenoid and snap spring mounting structure, as laterdescribed.

. Legs I9 of said base I3 extend downwardly between and in engagementwith the side edges of the spaced ears I1, Il of the respective sideframe members, and plate I8 is thereby held against rotation without thenecessity of welding or like means.

At the center of plate I8 is a square opening, bounded on two oppositesides by downwardly extending guide walls 25, 2U. l

Two arcuate side walls 2l, 2l diametrically placed, extend upwardly fromplate I8 to receive and position snap-spring retaining rings 22, 23 andthe cup 25 of a solenoid 26, said elements merely being set intoposition on said base plate I8, without securement thereto. As shown inFig. 5, ring 22 is shouldered for cooperation with the ring 23 toprovide a circular groove within which is confined the rim portion of asnap spring 24.

A second solenoid cup 2l houses a solenoid 28; between the solenoid cups25 and 2l are a pair of anged spacer members 29, 38, the outer iianges3l, 32 of which fit snugly /between and in contact with the frameside-pieces I5, I5, and the inner cylindrical anges 33, 34 provide aguide sleeve for a magnetic armature 35, axially slidable therein.

To'eachof the solenoid cups 25, 2l is attached a pole-piece 36, 31, theaxial passage of the latter being concentric with respect to thecylindrical flanges 33, 3d, to permit the guided slidable passage of theactuator rod 38, secured to armature 35.

The respective soienoid cups 25 and 21, ring members 29, 38, andpole-pieces 38, 31 are preferably of steel or other magnetic material.

The entire assembly previously described is maintained in properoperative position without individually securingr each of the respectiveele` ments by means of a bridge 40 which extends between the side framepieces I5, I6, to pass through a hole adjacentthe ends thereof, seeFigs. 4 and 5. One or more set screws 4|4I, pass through the bridge' 40to bear against solenoid cup 21, in this manner adjustably holding therespective solenoidpups, cup spacers and snap spring ring members inposition against the base plate I8. .Walls 2|, 2| of plate I8 preventthe rings 22, 23, and solenoid cup 25 from shifting laterally, and theside frame members I5, I6, against which the flanges 3l, 32 of sole-lnoid cup spacer rings 28, 30 abut, insure that the solenoid cup 21 isheld against movement.

The bridge 40 also serves to hold the cap I4 and casing I2 in position,by the screw 42.

Snap spring 24 has an opening through its center'to receive the reduceddiameter, threaded, end of the actuatior rod 38, which is secured to arectangular block 43 of insulation material, the latter passing throughthe square central opening in plate I8. The walls 20, 20 act as bearingguides for the block 43.

Secured to the other end of the block 43 by means to prevent relativerotation is a preferably at spring 44 which carries, by means of rivits'45, 45, see Fig. 1, a contact bridge 46 having at diametrically spacedlocations vcontacts 41, 41, said contacts cooperating with contacts 48,48 fixed to the insulating base II. Suitable terminal pieces 49 areprovided for connection of contacts, 48, 48-into the circuit to becontrolled.

'As Fig.` 3 shows, the rivets 45 are at a spacing of 90 with respect tothe contacts 41, 41. Such arrangement affords a substantial measure ofself-adjustability of contacts 41 with respect to contacts 48, 48, whileproviding an otherwise rigid-supporting structure for said contacts 41.

Referring to Fig. 7, the respective solenoids 26 and 28 are connectedinto a common circuit for remote control by a momentary-contact switchS, through the illustratedl terminals on cap I4. The contacts 41, 48 arein the circuit to be controlled. The solenoid coils may or may not bewound for low voltage actuation, according to preference. r

The actuation of solenoid 26 drives the armature to the right as shownin Fig. 5, thereby causing the snap spring 24 to throw into its secondposition of stable equilibrium as is shown in said figure and bringingthe contacts 41 into engagement with the terminal contacts 48. Thespring 44 iexes under thev impact of the contacts, acting to dampen theengagement of the said contacts and preventing rebound. Desirably, theengagement of the respective contacts is prior to the attainment of fullthrow `position of the snap spring, whereupon said snap spring to itsreverse position of equilibrium to open the contacts 41, 38. Thereaction of spring 44 assists in' the breaking of the contacts at highspeeds.

Whereas We have described our invention by reference to specific formsthereof, it will be understood vthat many changes and modiiications maybe made provided they do not depart from the scope of the claims Weclaim:

l. In an electromagnetic switch, the combination of spaced side framemembers, a sub-base carried -by and between said side frame members, asnap spring, means for mounting said snap spring disposed upon saidsub-base and conned between said side frame members, solenoid means foractuating said snap spring, and means for securing said solenoid meanswithin said side frame members, comprising a bridge member disposedacross said side frame members adjacent the ends thereof and meansassociated with said bridge means and said solenoid means for adjustablymaintaining said solenoid means in position with respect to saidsub-base.

2. In an electromagnetic switch, the combination of spaced side framemembers having ears struck inwardly and in a common plane, a subbasesupported on said ears, said sub-base having legs extending inwardlytherefrom in engagement with the said ears to hold said sub-base againstrotation, solenoid means supported by said sub-base, means including abridge member extending across said side frame members adjacent the endsthereof, and set screw means passing through said bridge member andbearing against said solenoid means to maintain the position thereof.

3. In an electromagnetic switch, the combinationof a base, side framemembers secured to said base in spacedrelationship, a sub-base supportedby and between said side frame members in fixed position thereon, snapspring supporting means carried on said sub-base, solenoid meansoperatively associated with said snap spring means and including cupmeans, said solenoid cup means being disposed one on the other, andmeans associated with said solenoid cup means and said side frame meansfor positioning said solenoid cup means therein.

4. In an electromagnetic switch, the combination of a base, side framemembers secured to said base in spaced relationship, a sub-basesupported by and between said side frame members in fixed positionthereon, snap spring supporting means carried on said sub-base, solenoidmeans operatively associated with said snap spring means and includingcup means, saidsolenoid cup means being disposed one on the other, meansassociated with said solenoid cup means and said side frame means forpositioning said solenoid cup means therein, said means including amember extending across said side frame means adjacent the end thereof,and a screw passing through said member and bearing against theimmediately adjacent solenoid cup means.

5. In an electromagnetic switch, the combination of a housingincluding-a base, side frame members secured to said base and extendingupwardly therefrom, a sub-base extending between said .side framemembers at a pre-determined xed position and individual solenoid cupmembers positioned one on the other with respect to said sub-base andmeans associated with said side frame members and bearing against one ofsaid solenoid cup means to retain said cup means upon said sub-base.

6. In an electromagnetic switch, the combination of a base, spaced sidemembers secured to said base and extending upwardly therefrom, asub-base positioned between and resting upon elements of said side framemembers, snap spring retaining means removably positioned on saidsub-base, a rigid solenoid housing disposed between said side framemembers and removably positioned upon said snap spring retaining means,a second rigid solenoid housing removably positioned upon the rst-namedhousing, a bridge member extending between and retained by said sideframe members, and means interposed between said bridge means and thelast-named solenoid housing to hold the respective solenoid housings andsnap spring retaining means in position upon said sub-base.

7. In an electromagnetic switch the combina'- tion of vspaced side framemembers, said mem-A bers having extensions projecting inwardly of saidmembers respectively, means for supporting said spaced side framemembers including a base, a sub-base supported upon said extensions anddisposed intermediate said spaced side frame members, operator means forsaid circuit breaker and disposed upon said sub-base, bridge meansspanning said side frame members and supported by said side framemembers, and securing means interposed between said bridge means andsaid operator means for stably positioning said operator means upon saidsub-base.

JOSEPH F. OBRIEN. EARL S. BOYNTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

